Trastuzumab is a monoclonal anti-human epidermal growth factor receptor 2 protein antibody used to treat HER2-positive breast, gastroesophageal, and gastric cancers.

Brand Names
Herceptin, Herceptin Hylecta, Herzuma, Kanjinti, Ontruzant, Perjeta-Herceptin, Phesgo, Trazimera
Generic Name
DrugBank Accession Number

Produced in CHO cell cultures, trastuzumab is a recombinant IgG1 kappa, humanized monoclonal antibody 6 that selectively binds with high affinity in a cell-based assay (Kd = 5 nM) to the extracellular domain of the human epidermal growth factor receptor protein (HER2).12 It is used as a treatment of human epidermal growth factor receptor (HER)-2+ metastatic breast cancer, where there is a proven amplification of the HER-2 oncogene or over-expression of the HER-2 protein in tumours. It is suggested that the overexpression or gene amplification of HER2 has been found in about 20–30% of breast cancers and elevated activation of HER2 triggers multiple downstream pathways leading to abnormal proliferation of cancer cells 4. Trastuzumab binds to HER2 and suppresses cancer cell growth, proliferation, and survival directly and indirectly 4.

In December 2017, FDA approved OGIVRI (trastuzumab-dkst) as a biosimilar to Herceptin (trastuzumab) for the treatment of patients with breast or metastatic stomach cancer (gastric or gastroesophageal junction adenocarcinoma) whose tumors overexpress the HER2 gene (HER2+). It displays biosimilar properties as Herceptin according to clinical data. While Ogivri is the first biosimilar approved in the U.S. for the treatment of breast cancer or stomach cancer, it is the second biosimilar approved in the U.S. for the treatment of cancer. Herzuma (trastuzumab-pkrb) is a biosimilar drug approved in December 2018 for the treatment of HER2-overexpressing breast cancer. KANJINTI (trastuzumab-anns) is another biosimilar approved by the FDA in June 2019.16 ONTRUZANT, another biosimilar of Herceptin, was approved by Health Canada in February 2022.22,23 In November 2023, trastuzumab was also approved by the EMA under the brand name Herwenda.25

Approved, Investigational
Biologic Classification
Protein Based Therapies
Monoclonal antibody (mAb)
Protein Structure
Protein Chemical Formula
Protein Average Weight
145531.5 Da
>Anti-HER2 Light chain (1 and 2)
>Anti-HER2 Heavy chain (1 and 2)
Download FASTA Format
  • Trastuzumab
  • trastuzumab-anns
  • trastuzumab-dkst
  • trastuzumab-dttb
  • trastuzumab-pkrb
  • trastuzumab-qyyp
External IDs
  • 4D5V8
  • ABP 980
  • ABP-980
  • DMB-3111
  • EG-12014
  • EG12014
  • R-597
  • SB-3
  • SYD-977
  • SYD977



For the adjuvant treatment of HER2-overexpressing breast cancer, trastuzumab is indicated in several clinical settings: as part of a treatment regimen consisting of doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel; as part of a treatment regimen with docetaxel and carboplatin; or as monotherapy following multi-modality anthracycline-based therapy.12

Trastuzumab is indicated as a first-line treatment, in combination with paclitaxel, for metastatic HER2-overexpressing breast cancer, and as monotherapy in patients who have previously received one or more chemotherapy regimens in the metastatic setting.12 In Europe, trastuzumab can also be used in combination with paclitaxel or docetaxel for the treatment of metastatic HER2-positive breast cancer in adult patients and with an aromatase inhibitor in postmenopausal patients.24

For HER2-positive early breast cancer, the EMA approved trastuzumab as monotherapy following surgery, chemotherapy (neoadjuvant or adjuvant), and radiation or following adjuvant chemotherapy with doxorubicin and cyclophosphamide in combination with paclitaxel or docetaxel. It can also be used in combination with adjuvant chemotherapy consisting of docetaxel and carboplatin or with neoadjuvant chemotherapy followed by adjuvant trastuzumab therapy for locally advanced (including inflammatory) disease or tumors > 2 cm in diameter.24

Trastuzumab is also indicated, in combination with cisplatin and capecitabine or 5-fluorouracil, for the treatment of patients with HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma who have not received prior treatment for metastatic disease by the FDA and EMA.12

Trastuzumab is indicated for subcutaneous administration - in combination with either hyaluronidase15 or both hyaluronidase and pertuzumab20 - for the treatment of adults with HER2-positive breast cancers.

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Associated Conditions
Indication TypeIndicationCombined Product DetailsApproval LevelAge GroupPatient CharacteristicsDose Form
Used in combination to treatBreast cancerCombination Product in combination with: Hyaluronidase (human recombinant) (DB06205)•••••••••••••••••••••
Treatment ofBreast cancer•••••••••••••••••••••
Used in combination to treatBreast cancerRegimen in combination with: Carboplatin (DB00958), Docetaxel (DB01248)•••••••••••••••••••••• ••••••• ••• ••••••••
Used in combination to treatBreast cancerRegimen in combination with: Docetaxel (DB01248), Paclitaxel (DB01229)•••••••••••••••• •••••••••••• •••• ••••••••••• ••• •••••••••••••••••••••••••• ••••••• ••• ••••••••
Treatment ofBreast cancer•••••••••••••••••••• ••••••••••••••••••••••••••• ••••••• ••• ••••••••
Contraindications & Blackbox Warnings
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Trastuzumab exerts an antitumour activity and is used in the treatment of HER2-positive breast cancer. HER2 protein overexpression is observed in 20%-30% of primary breast cancers 7 thus HER2 presents as a useful therapeutic target for the treatment of breast cancers. Trastuzumab has been shown, in both in vitro assays and in animals, to inhibit the proliferation of human tumour cells that overexpress HER2. It works as a mediator of antibody-dependent cellular cytotoxicity, where it binds as an antibody to cells over-expressing HER2, leading to preferential cell death. Trastuzumab was also shown to inhibit angiogenesis of tumor cells in vivo 4. Higher doses and longer dosing intervals show no significant benefit over standard dose schedules 6. In patients with HER2 positive solid tumours, trastuzumab did not exert any clinically significant QTc interval duration.12

Mechanism of action

Trastuzumab is a recombinant humanized IgG1 monoclonal antibody against the HER-2 receptor, a member of the epidermal growth factor receptors which is a photo-oncogene. Over-expressed in breast tumour cells, HER-2 overamplifies the signal provided by other receptors of the HER family by forming heterodimers 4. The HER-2 receptor is a transmembrane tyrosine kinase receptor that consists of an extracellular ligand-binding domain, a transmembrane region, and an intracellular or cytoplasmic tyrosine kinase domain. It is activated by the formation of homodimers or heterodimers with other EGFR proteins, leading to dimerization and autophosphorylation and/or transphosphorylation of specific tyrosine residues in EGFR intracellular domains 4. Further downstream molecular signaling cascades are activated, such as the Ras/Raf/mitogen-activated protein kinase (MAPK), the phosphoinositide 3-kinase/Akt, and the phospholipase Cγ (PLCγ)/protein kinase C (PKC) pathways that promote cell growth and survival and cell cycle progression 4. Due to upregulation of HER-2 in tumour cells, hyperactivation of these signaling pathways and abnormal cell proliferation is observed. Trastuzumab binds to the extracellular ligand-binding domain and blocks the cleavage of the extracellular domain of HER-2 to induce its antibody-induced receptor downmodulation 4, and subsequently inhibits HER-2-mediated intracellular signaling cascades. Inhibition of MAPK and PI3K/Akt pathways lead to an increase in cell cycle arrest, and the suppression of cell growth and proliferation 4. Trastuzumab also mediates the activation of antibody-dependent cell-mediated cytotoxicity (ADCC) 6 by attracting the immune cells, such as natural killer (NK) cells, to tumor sites that overexpress HER-2 4. While the drug alone has a minimal potential to induce complement-dependent cytotoxicity (CDC),8 one study demonstrated increased therapeutic effectiveness and a synergistic effect on uterine serous carcinoma cells in vitro when used in combination with pertuzumab, which also has minor effects on CDC alone. This study showed that only the combination of both cell-bound antibodies would be sufficient to bind and activate the complement component 1q (C1q) required to initiate the complement cascade reaction.9

Intrinsic trastuzumab resistance has been noted for some patients with HER-2 positive breast cancer. Mechanisms involving trastuzumab resistance include deficiency of phosphatase and tensin homologue and activation of phosphoinositide 3-kinase, and the overexpression of other surface receptors, such as insulin-like growth factor 6.

AReceptor tyrosine-protein kinase erbB-2

Peak and trough plasma concentrations at steady state (between weeks 16 and 32) were approximately 123 and 79 mcg/mL, respectively. At the highest weekly dose studied (500 mg), mean peak serum concentration was 377 mcg/mL.12

Volume of distribution

Not Available

Protein binding

Not Available


After it binds to HER2, trastuzumab is metabolized intracellularly into smaller peptides and amino acids.6

Route of elimination

Following metabolism, the complex elimination of trastuzumab in humans is mediated by epithelial cells in a dose-dependent (nonlinear) fashion.6 The renal excretion of trastuzumab is very low.6


The terminal half-life is approximately 28 days,6 but may decrease with lower doses - at the 10mg and 500mg doses, half-lives averaged approximately 1.7 and 12 days, respectively.11


The predicted steady-state clearance of trastuzumab is 0.173 - 0.337 L/day, dependent primarily on the dosing regimen.12 The clearance rate for subcutaneously administered trastuzumab, formulated with hyaluronidase for improved subcutaneous absorption, is 0.11 L/day.15

Adverse Effects
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There is no experience with overdosage of trastuzumab in clinical trials - single doses >8 mg/kg have not been tested in humans.12 Trastuzumab can contribute to the development of ventricular dysfunction and congestive heart failure, particularly when used in combination (or temporally adjacent) to other cardiotoxic chemotherapies such as anthracyclines.12

Trastuzumab Action PathwayDrug action
Pharmacogenomic Effects/ADRs
Interacting Gene/EnzymeAllele nameGenotype(s)Defining Change(s)Type(s)DescriptionDetails
Receptor tyrosine-protein kinase erbB-2---(A;G)G Allele, heterozygoteADR Directly StudiedPatients with this genotype have increased risk of cardiotoxicity with trastuzumab.Details


Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
AbataceptThe risk or severity of neutropenia can be increased when Trastuzumab is combined with Abatacept.
AbciximabThe risk or severity of adverse effects can be increased when Abciximab is combined with Trastuzumab.
AcetyldigitoxinAcetyldigitoxin may decrease the cardiotoxic activities of Trastuzumab.
AdalimumabThe risk or severity of neutropenia can be increased when Trastuzumab is combined with Adalimumab.
Adenovirus type 7 vaccine liveThe risk or severity of infection can be increased when Adenovirus type 7 vaccine live is combined with Trastuzumab.
Food Interactions
No interactions found.


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International/Other Brands
Herclon (Roche)
Brand Name Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
HerceptinInjection, powder, lyophilized, for solution150 mg/7.4mLIntravenousGenentech, Inc.2017-02-10Not applicableUS flag
HerceptinPowder, for solution440 mg / vialIntravenousHoffmann La Roche1999-08-23Not applicableCanada flag
HerceptinInjection, powder, for solution150 mgIntravenousRoche Registration Gmb H2016-09-08Not applicableEU flag
HerceptinInjection150 mg/7.4mLIntravenousGenentech, Inc.1998-09-25Not applicableUS flag
Herceptin420 mg/20mLIntravenousGenentech, Inc.1998-09-25Not applicableUS flag
Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
Herceptin HylectaTrastuzumab (600 mg/5mL) + Hyaluronidase (human recombinant) (10000 U/5mL)Injection, solutionSubcutaneousGenentech, Inc.2019-02-28Not applicableUS flag
OgivriTrastuzumab (440 mg / vial) + Water (20 mL / vial)Powder, for solutionIntravenousBiosimilar Collaborations Ireland Limited2019-06-06Not applicableCanada flag
Perjeta-herceptinTrastuzumab (440 mg / vial) + Pertuzumab (420 mg / 14 mL)Kit; Powder, for solution; SolutionIntravenousHoffmann La Roche2013-05-09Not applicableCanada flag
PhesgoTrastuzumab (60 mg / mL) + Pertuzumab (60 mg / mL)SolutionSubcutaneousHoffmann La Roche2021-04-09Not applicableCanada flag
PhesgoTrastuzumab (600 mg) + Pertuzumab (600 mg)Injection, solutionSubcutaneousRoche Registration Gmb H2021-01-28Not applicableEU flag


ATC Codes
L01FD01 — TrastuzumabL01FY01 — Pertuzumab and trastuzumab
Drug Categories
Chemical TaxonomyProvided by Classyfire
Not Available
Organic Compounds
Super Class
Organic Acids
Carboxylic Acids and Derivatives
Sub Class
Amino Acids, Peptides, and Analogues
Direct Parent
Alternative Parents
Not Available
Not Available
Molecular Framework
Not Available
External Descriptors
Not Available
Affected organisms
  • Humans and other mammals

Chemical Identifiers

CAS number


General References
  1. Bange J, Zwick E, Ullrich A: Molecular targets for breast cancer therapy and prevention. Nat Med. 2001 May;7(5):548-52. [Article]
  2. Menard S, Pupa SM, Campiglio M, Tagliabue E: Biologic and therapeutic role of HER2 in cancer. Oncogene. 2003 Sep 29;22(42):6570-8. [Article]
  3. Kute T, Lack CM, Willingham M, Bishwokama B, Williams H, Barrett K, Mitchell T, Vaughn JP: Development of Herceptin resistance in breast cancer cells. Cytometry A. 2004 Feb;57(2):86-93. [Article]
  4. Albanell J, Codony J, Rovira A, Mellado B, Gascon P: Mechanism of action of anti-HER2 monoclonal antibodies: scientific update on trastuzumab and 2C4. Adv Exp Med Biol. 2003;532:253-68. [Article]
  5. Tan AR, Swain SM: Ongoing adjuvant trials with trastuzumab in breast cancer. Semin Oncol. 2003 Oct;30(5 Suppl 16):54-64. [Article]
  6. Boekhout AH, Beijnen JH, Schellens JH: Trastuzumab. Oncologist. 2011;16(6):800-10. doi: 10.1634/theoncologist.2010-0035. Epub 2011 May 31. [Article]
  7. Vu T, Claret FX: Trastuzumab: updated mechanisms of action and resistance in breast cancer. Front Oncol. 2012 Jun 18;2:62. doi: 10.3389/fonc.2012.00062. eCollection 2012. [Article]
  8. Rogers LM, Veeramani S, Weiner GJ: Complement in monoclonal antibody therapy of cancer. Immunol Res. 2014 Aug;59(1-3):203-10. doi: 10.1007/s12026-014-8542-z. [Article]
  9. Mamidi S, Cinci M, Hasmann M, Fehring V, Kirschfink M: Lipoplex mediated silencing of membrane regulators (CD46, CD55 and CD59) enhances complement-dependent anti-tumor activity of trastuzumab and pertuzumab. Mol Oncol. 2013 Jun;7(3):580-94. doi: 10.1016/j.molonc.2013.02.011. Epub 2013 Feb 20. [Article]
  10. US Patent US6870034B2 (includes Trastuzumab heavy chain sequence) [Link]
  11. Health Canada Product Monograph: Ogivri (trastuzumab) powder for intravenous infusion [Link]
  12. FDA Approved Drug Products: Herceptin (trastuzumab) for intravenous injection [Link]
  13. FDA Approved Drug Products: Ogivri (trastuzumab-dkst) for intravenous infusion [Link]
  14. FDA Approved Drug Products: Herzuma (trastuzumab-pkrb) for intravenous infusion [Link]
  15. FDA Approved Drug Products: Herceptin Hylecta (trastuzumab and hyaluronidase-oysk) for subcutaneous injection [Link]
  16. FDA Approved Drug Products: Kanjinti (trastuzumab-anns) for intravenous infusion [Link]
  17. FDA Approved Drug Products: Ontruzant (trastuzumab-dttb) for intravenous infusion [Link]
  18. FDA Approved Drug Products: Trazimera (trastuzumab-qyyp) for intravenous infusion [Link]
  19. Genentech: Herceptin(R) MSDS [Link]
  20. FDA News Release: FDA Approves Breast Cancer Treatment That Can Be Administered At Home By Health Care Professional [Link]
  21. FDA Approved Drug Products: Phesgo (pertuzumab/trastuzumab/hyaluronidase-zzxf) for subcutaneous injection [Link]
  22. Health Canada Product Monograph: ONTRUZANT (trastuzumab) intravenous infusion [Link]
  23. GlobeNewsWire: Samsung Bioepis Announces Health Canada Approval of 150mg Single-use Vial and 440mg Multi-dose Vial of ONTRUZANT® (SB3), Trastuzumab Biosimilar for the Treatment of Adults with Early Breast Cancer, Metastatic Breast Cancer, and Metastatic Gastric Cancer [Link]
  24. EMA Product Information: HERWENDA (trastuzumab) Powder for concentrate for solution for infusion (December 2023) [Link]
  25. An overview of Herwenda and why it is authorised in the EU [Link]
  26. Trastuzumab: Antineoplastic agent; a recombinant DNA- derived humanized anti-HER2 monoclonal antibody (complete heavy chain sequence) [File]
PubChem Substance
Therapeutic Targets Database
RxList Drug Page Drug Page
Download (320 KB)

Clinical Trials

Clinical Trials
Clinical Trial & Rare Diseases Add-on Data Package
Explore 4,000+ rare diseases, orphan drugs & condition pairs, clinical trial why stopped data, & more. Preview package
PhaseStatusPurposeConditionsCountStart DateWhy Stopped100+ additional columns
4CompletedDiagnosticBreast Cancer1somestatusstop reasonjust information to hide
4CompletedTreatmentBreast Cancer4somestatusstop reasonjust information to hide
4RecruitingDiagnosticAnatomic Stage IV Breast Cancer AJCC v8 / Brain Metastases / Metastatic Breast Carcinoma1somestatusstop reasonjust information to hide
4RecruitingTreatmentAdvanced Breast Cancer / HER2/Neu-positive Breast Cancer1somestatusstop reasonjust information to hide
4RecruitingTreatmentBreast Cancer3somestatusstop reasonjust information to hide


Not Available
  • DSM Corp.
  • F Hoffmann-La Roche Ltd.
  • Genentech Inc.
Dosage Forms
InjectionParenteral150 mg
InjectionIntravenous150 mg/7.4mL
InjectionParenteral600 MG/5ML
Injection, powder, for solutionIntravenous
Injection, powder, lyophilized, for solutionIntravenous150 mg/7.4mL
Injection, solutionParenteral; Subcutaneous600 MG
Injection, solutionParenteral; Subcutaneous600 MG/5ML
Powder, for solutionIntravenous440 mg / vial
Injection, solution600 mg/5ml
Injection, powder, lyophilized, for solutionIntravenous44000000 mg
Injection, solutionSubcutaneous600 mg/5mL
Injection, solutionSubcutaneous
Injection, powder, for solutionIntravenous440 mg
SolutionSubcutaneous600 mg / 5 mL
SolutionSubcutaneous600.00 mg
Injection, solutionSubcutaneous600 mg
SolutionSubcutaneous600 mg
Injection, powder, for solution440 mg
Injection, powder, for solutionIntravenous420 mg
Kit; powder, for solutionIntravenous440 mg / vial
SolutionIntravenous150.00 mg
Injection, powder, for solutionIntravenous150 mg/1vial
Injection, solution, concentrateIntravenous150 mg
Injection, powder, lyophilized, for solutionIntravenous150 mg
Injection, powder, for solution
Injection, powder, for solution160 mg/1vial
Injection, powder, lyophilized, for solutionIntravenous150 mg/7.15mL
Injection, powder, lyophilized, for solutionIntravenous420 mg/20mL
Kit; powder, for solutionIntravenous420 mg / vial
Injection, powder, for solution150 mg
Injection, powder, for solutionIntravenous150 mg
Injection, powder, for solutionIntravenous; Parenteral150 MG
Powder, for solutionIntravenous
Powder, for solutionIntravenous150 mg / vial
Injection, powder, for solutionIntravenous; Parenteral420 MG
Injection, powder, lyophilized, for solutionIntravenous150 mg/1
KitIntravenous420 mg/1
Powder, for solutionIntravenous150 mg
Powder, for solutionIntravenous420 mg
Kit; powder, for solution; solutionIntravenous
SolutionSubcutaneous6000000 mg
Injection, powder, lyophilized, for solution; kitIntravenous420 mg/20mL
Injection, solution, concentrateIntravenous150 mg/1vial
Injection, solution, concentrateIntravenous440 mg/1vial
Injection, powder, lyophilized, for solutionIntravenous440 mg
SolutionIntravenous440.00 mg
Injection, powder, lyophilized, for solutionIntravenous
Injection, powder, for solutionIntravenous60 mg
Injection, powder, for solutionIntravenous; Parenteral60 mg
Injection, powder, for solutionIntravenous440 mg/1vial
PowderIntravenous440 mg/1bottle
PowderIntravenous150 mg/1vial
PowderIntravenous150 mg/1bottle
Injection, powder, for solution100 mg/1vial
Unit descriptionCostUnit
Herceptin 440 mg Solution Vial3581.2USD vial
Herceptin 440 mg vial3443.46USD vial
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patent NumberPediatric ExtensionApprovedExpires (estimated)Region
CA2103059No2005-03-222012-06-15Canada flag


Experimental Properties
melting point (°C)61 °C (FAB fragment), 71 °C (whole mAb)Vermeer, A.W.P. & Norde, W., Biophys. J. 78:394-404 (2000)


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Pharmacological action
General Function
Transmembrane signaling receptor activity
Specific Function
Protein tyrosine kinase that is part of several cell surface receptor complexes, but that apparently needs a coreceptor for ligand binding. Essential component of a neuregulin-receptor complex, alt...
Gene Name
Uniprot ID
Uniprot Name
Receptor tyrosine-protein kinase erbB-2
Molecular Weight
137909.27 Da
  1. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [Article]
  2. Leveque D, Gigou L, Bergerat JP: Clinical pharmacology of trastuzumab. Curr Clin Pharmacol. 2008 Jan;3(1):51-5. [Article]
  3. Lin A, Rugo HS: The role of trastuzumab in early stage breast cancer: current data and treatment recommendations. Curr Treat Options Oncol. 2007 Feb;8(1):47-60. [Article]
  4. Treish I, Schwartz R, Lindley C: Pharmacology and therapeutic use of trastuzumab in breast cancer. Am J Health Syst Pharm. 2000 Nov 15;57(22):2063-76; quiz 2077-9. [Article]

Drug created at June 13, 2005 13:24 / Updated at April 09, 2024 18:11